The Mercedes-AMG A45 4Matic is the halo car of the new A-Class. In style and substance the compact is in a class of its own, taking the hot hatch to a new level. Getting straight to the nub of the matter, the car is powered by the world's most powerful production four-cylinder passenger car engine.

A turbocharged 2.0-litre unit from Mercedes-Benz's performance arm AMG, the engine pumps out 280kW of power and 475Nm of torque. That's enough to spear the car from rest to 100 km/h in just 4.2 seconds.

AMG has had a hand in everything, from styling to safety. The Mercedes-AMG A45 arrives with 19-inch AMG wheels, AMG Performance Seats (heated up front), AMG Performance Exhaust, AMG Dynamic Select, which includes Race Mode, Comand Navigation and Harman Kardon Distronic Plus as standard.

As with all good sports cars the Mercedes-AMG A45 4Matic focuses on the driver

The cost of all this whiz-bangery is an eye-watering (for a compact hatch) 80 grand-plus on the road. My time with the test car was priceless.

Design

Striking lines, dynamically curved surfaces and coupe-like windows characterise the latest A-Class models. AMG handiwork on the hero A45 includes an added lip on the roof spoiler for increased downforce; AMG front bumper in A-wing design specific to the car; rear bumper with new diffuser insert with four vertical fins and a diffuser spoiler lip.

It rides on AMG cross-spoke titanium grey alloy wheels with 235/35 R19 tyres on 8 J x 19 rims;-specific radiator grille with silver-chrome double louvre and ‘AMG' lettering; matte titanium grey front splitter; LED high-performance headlamps; cooling air vents, each with two fins and a black flic for optimal routing of cooling air.

As with all good sports cars the Mercedes-AMG A45 4Matic focuses on the driver and the information and controls he or she needs to enjoy a dynamic driving experience.

To this effect, front and centre is an instrument cluster that gives vital details in a clear and concise manner in a two-tube format. The AMG Drive Unit with AMG Dynamic Select controller for choosing one of the five drive modes - Comfort, Sport, Sport +, Individual and Race – is positioned close at hand on the centre console, while an AMG performance steering wheel in black Nappa leather perfectly matches the AMG performance seats in black Red Cut leather upholstery.

Features

A Comand Package consists of Comand Online with am 8-inch colour display, HDD navigation with RDS-TMC, single-disc DVD player with MP3 / WMA / AAC compatibility, AM / FM tuner, Linguatronic voice control operation, Bluetooth and internet connectivity and USB connectivity, with two ports in the centre console.

The new-generation A-Class is the first Mercedes range to be available with smartphone integration; Apple CarPlay, which runs iPhone, navigation and music, receiving and sending text messages and emails, as well as incorporating Siri voice control.

Harman Kardon Logic 7 surround sound system, including 12 speakers and Dolby Digital 5, complete the hi-tech credentials of the car.

Engine / Transmission

The most powerful production four-cylinder passenger car engine in the world is fitted with an AMG Performance exhaust system producing enhanced sound and motor racing feeling. An AMG Speedshift dual clutch seven-speed sports transmission completes the picture.

AMG speed-sensitive sports steering has two characteristic curves working in conjunction with AMG Ride Control sports suspension with two-stage adaptive damping. An optional AMG Dynamic Plus package, including AMG limited-slip differential, can add even more to lateral dynamics.

The term 4Matic in Mercedes' speak refers to all-wheel drive. Something that's necessary in a car with this tremendous power output - trying to drive it only through two weeks would have been a tyre-shredding disaster.

The engine was blipping enthusiastically on gear changes. Soul-stirring stuff.

Safety

With numerous driving assistance systems, from drowsiness detection with Attention Assist to Distronic Plus, the A-Class provides occupants with comprehensive protection.

Safety technology including nine airbags, pre-safe, blind spot assist, autonomous emergency braking (AEB) and an active bonnet. The Mercedes-AMG A45 4Matic also arrives with lane keeping assist (passive) as standard.

Driving

The Mercedes-AMG A45 4Matic crouched in the driveway, challenging any driver to push its limits. Did I do so? I wouldn't say so even if I did. Let's say the engine was blipping enthusiastically on gear changes. Soul-stirring stuff.

Playtime consisted of scrolling through the Dynamic Select system, with Comfort well suited to stop / start going. Sport and Sport+ had things bubbling with a pleasing combination of peppy performance and firm and responsive ride and steering, while Race with its bone-jarring stiffness, was better left for a later track days on ultra-smooth surfaces.

Mercedes-AMG A45 4Matic officially consumes fuel at the rate of 7.3 to 6.9 litres per 100 kilometres, on the combined urban / highway cycle, with carbon dioxide emissions at 171 to 162 grams per kilometre.

On test, Comfort mode was just that around town, the car clocking up 10 to 12 litres per 100 in fuel use, while shifting up to the Sport modes had the AMG power feeding on 16 to 20 litres per 100 kilometres, not surprising considering the grunt generated. Best consumption on the motorway was 6.8 litres.

Black leather seats were super squeezy, the swoopy roof limited rear-seat head room and the occupants here fell short of leg space if front seat occupants were above average height.